Variable-speed mechanism.



J. H. BMMSON.

VARIABLE SPEED MECHANISM.

APPLICATION FILED 1113.10, 1913.

Patented June 30, 1914.

3 SHEETS-SHEET 1.

L31} 2 mi 8 Patented June 30,1914.

3 BEEBTS"SHEET 2.

I. mm 1 mm mm llll flhllll lfilliilllllljlr .i m W wimsgsis: flW/figaQM/WHNVENTOR ATTORNEY J. H. BRIMSON.

VARIABLE SPEED MECHANISM.

A15PLIGATI0N FILED FEB. 10, 1913. 1JL681 Q r Patented June 30, 19M.

3 SHEETSSHEET 3.

8 Y E f Y GAME A E I El y/kw BY ATTOHN PAfiENT .FETQE.

JAMES-H. BRIMSON, OE SAGINAW, MICHIGAN, ASSIGNOR 0F ONE-HALF TO WILLIA1VI H. HART, OF SAGINAW, MICHIGAN.

VALBIABLE-SPEEE MECHANISM.

Specification of Letters Patent.

Patented June 3d, time.

gears and transmissions such as are commonly employed in the transmission mechanism of automobiles and like machinery, in which a number of speeds ahead are required and one or more speeds to reverse.

The objects of my invention are, first, to provide a change speed gear in which the speed is changed by throwing gears of different speed ratios into and out of operation, but so constructing the mechanism that the teeth or the gears are not disengaged or slid into mesh when speed change occurs,

thus saving wear on the teeth and reducing liability of breakage.

A further object is to provide a change speed device in which all of the gears are rotating all of the time when the machine is in operation, so that the shift from one speed to another may be made while the gears are in motion, it being unnecessary to start a gear from rest when a shift in speed is to be made.

With these and certain other objects in view which will appear later in the specification, my invention consists in the devices described and claimed and the equivalents thereof.

on line t-d of Fig. 6 through the loose gears and the drive shaft; Fig. 5 is an end view of the same with the collar and'ke s removed; Fig. 6 is an end view of t stepped cone or drum, the gears bein removed; Fig. 7 is a diagrammatic view 0 the reverse gears; Fig. 8 is a view of one of the loose gears Fig. 9 is an end view of one of the sleeves that hold the loose gears on the drum; Fig. 10 is a perspective detail of a shifting-key; Fig. 11 is a part sectional detail through the hub and shaft, showing the shifting-key in position to drive the reverse gear; Fig. 12 is a similar view showing the key in position to drive the slow speed gear;

'in position to drive the intermediate gear; 14 shows the key in position to drive the shaft 1 at high speed, which is the speed of the motor.

As is clearly shown in the drawings, the device consists in a main shaft 1, counter shaft 2, and an idler shaft 8, upon which appropriate gears are mounted. At one end of the main shaft 1 and mounted to revolve loosely thereon is a drive gear 41 having a quill hub- 5, to which the driving power may be applied in any suitable manner, as by ,means of a drive pulley 6 or any suitable clutch fixed to the quill 5. The quill 5 may be mounted in suitable anti-friction bear- ?ings 7. Upon shaft 1 is a stepped cone or drum 8, and upon this drum a plurality of gears are loosely mounted, each gear being icapable of revolving on the drum, as on a journal. Any desired or convenient number of gears of various diameters may be employed, but for purpose of illustration l ,have shown three such gears, of which 9 is the intermediate speed gear; 10 the slow jspeed gear; and 11 the reverse gear. The

imanner in which these gears are actuated 1 will be described later.

The counter shaft 2' carries a driven gear 512 that meshes with gear 4 and a gear 13 =that meshes with gear 9; also a gear 14 Emeshing" with gear 10 and a gear 15 that ,meshes' with a pinion 16 fixed to the idler -"shaft 3'. All of the gears on shaft 2 are rigidly fined to it. Fixed to idler shaft 3 and adjacent to pinion 16 is a second pinion 17 Fig. 3) that meshes with the reverse gear 11 on shaft 1.

When gear 4 is rotated by the motor or ;other source of power, it rotates ears 13,

I l and 15, and these gears respectively rotate the loose geai st) and 10 in one direction Fig. 13 is a similar view showing the key and gear 11 (through pinions .16 and 17) in the opposite direction. 1

Since shaft 1 is revoluble within the quill 5 and since all of the gears 9, 10 and 11 are revoluble on the drum 8, which is fixed to shaft 1, no power will be transmitted by shaft 1 until one or the other of the gears 4 9, 10, or 11 is locked to that drum.

The means by which any one of these gears may be locked to the drum while all the others remain loose will now be described. The drum, as shown in Figs. 4 and 6, consists in a series of stepped cylindrical bearings upon which the gears 9, 10 and 11 may rotate. These gears are without spokes or hubs, consisting merely of annular rings with external gear teeth. Gear 11 is held in place on the drum by a collar 18,- gear 10 by sleeve 19 keyed or otherwise secured to the drum; gear 9 by sleeve 20. To look any one of these gears to the drum, I form the drum with one or more radial slots 21, within each of which is slidingly received a key 22. In practice I prefer to provide four such slots as shown 1n Fig. 6 and to provide four corresponding keys, the ends of which are secured to a sliding collar 23, so that all four keys may be slid in and out along the slots 21 when the collar is moved lengthwise shaft 1. Each key is formed with an'outwardly projecting lug 24 and a similar, but smaller lug 25. Each of the drum gears, as 11, has its interior rim formed with slots 26, see Fig. 8, to receive the corresponding lug, as 24, of the key 22, the side walls of the slots forming shoulders to be engaged by the sides of the lugs when the lugs are inserted in the slots. When a lug, as 24, has entered the corresponding slot, as 26, of gear 11 (see Fig. 11) and the gear is rotated by means of its corresponding gear 15 (Fig. 1) and the pinions 16 and 17, shaft 1 will be positively rotated in the opposite direction to that of the drive gear 4. When the key is pushed in so that projection 24 engages the slot of gear 10, as shown in Fig. 12 shaft 1 will be driven at slow speed in the same direction as gear v 4. When the key is moved until projection 25 registers with the slot of gear 9, as shown in Fig. 13, shaft 1 will be driven in the same direction as gear 4, but at an intermediate speed. When the key is moved so that projection 25 engages the recess 27 of gear 4, as shown in Fig. 14, shaft" 1 will be driven in the same direction and at the same speed as gear 4, this beinghigh speed. The spacing apart of gears 4, 9, 10 and 11 and the spacing apart of projections 24 and 25 on the key 22 are such that between each of the adjustments above described both of the projections will be out of engagement with the gears, allowing all the gears to rotate without dri ing shaft 1. This is to insure that I in changing speed by shifting the key, each gear will be thrown out ofaction before the next gear is thrown in. In practice I prefer t0 bevel one wall of each slot 26, as at 28in Fig. 5, to facilitate the entering of the projection. T 0 shift the collar 23 and thereby toshift keys 22, I provide an arm 29, (Fig.

' 1) or equivalent member that may be mounted on any suitable support, as a 1011 itudinally movable shaft 30 and this sha t may be actuated by any suitable means. An incidental advantage of this construction is that the shaft 30 or any equivalent shifting device may be located at almost any desired point around the circumference of the gears on shaft 1. This construction enables the handling mechanism by which shaft 30 is to be actuated, to be located at almost any convenient or accessible place about the mechamsm. iHaving described my invention, what I ilesire to secure by Letters Patent is as folows:

1. In a variable speed device, a main shaft carrying a stepped cone, a drive gear rev-= oluble thereon; a counter shaft havmg gears fixed thereon; said cone having radial slots formed therein and located outside the periphery of the shaft; gears of various diameters revolubly mounted on the successive steps of the cone and permanently meshing with the gears on the-counter shaft; keys slidingly received in the slots of said cone,

each key formed with a plurality of outwardly projecting lugs; each gear on said cone having an interior rim formed with transverse slots to receive said lugs, and means for simultaneously moving said keys along their slots.

2. In a variable speed device of the class described, having a main shaft carrying a stepped cone, a plurality of gears of various diameters spaced apart and revolubly mounted on the respective steps of said cone, said cone formed with a plurality of radial slots extending lengthwise, but located outside the periphery of the shaft; keys slidingly re ceived in the slots of said cone, each key formed with a plurality of outwardly projecting lugs of various heights and spaced apart, whereby all the lugs are adapted to be thrown out of engagement with the gears when the keys are in intermediate position.

3. In a variable speed device, the combination with a counter shaft having gears fixed thereon, a main shaft carryin a stepped cone, and a drive gear revolu le on said shaft, said cone having radial slots formed therein and located outside the periphery of the shaft; gears of various diameters revolubly mounted on the respective steps of the cone and permanently meshing with the gears on the counter shaft, said gears being spaced apart along said cone; keys slidingly received in the slots of said cone, each key formed with a plurality of outwardly pro- In testimony whereof, I afix my signature jecting lugs of various heights, said lugs in presence ofitwo witnesses. spaced apart along said keyseach gear on said cone having an interioi' rim formed JAMES BRIMSON' s with transverse slots to receive said lugs, Witnesses:

and means for simultaneously moving said NELLIE M. ANGUS,

Joe. V. CARPENTER.

keys along their slots. 

